It looks like you have inadvertently locked you post. As for your questions, As a scroll saw instructor, I start my beginner students of using 3/4" pine. It is cheap and easy to cut. As far as blades, a #5 skip tooth blade is the best blade to start off with. Either an Olson #5 skip tooth or a Flying Dutchman Polar #5. After you get the hang of the saw you can start trying different hardwoods and plywoods in different thicknesses, and different blade sizes and types.
You can find Flying Dutchman Blades at
www.mikesworkshop.com. You can find Olson blades at any woodworking store or at
www.sloanswoodshop.comBTW. welcome to the forum! Please go to the introduction page and introduce yourself so we can better welcome you!